The present invention relates to electronic control apparatuses and methods, and more particularly to a program rewriting control and devices therefor which disables unauthorized rewriting of programs.
Many electronic control apparatuses are proposed for preventing intrusion into automotive vehicles and burglary of the same. In some apparatuses, an identification code (ID) of a key which a vehicle user uses is compared with a key ID which is stored in a non-volatile electrically erasable programmable read-only memory (EEPROM) of an electronic control unit (ECU) for engine control. Engine operations such as fuel injection and ignition are prohibited, if the compared key Ids do not agree or coincide.
It is a recent trend to design ECUs to be capable of rewriting or updating engine control programs stored in respective EEPROMs by using program rewriting tools. Thus, any defects in the control program of the ECU can be rectified without entirely replacing the ECU with a new one.
The program rewriting tool may be used to illegally rewrite the control program. That is, it may be used to rewrite control programs having an anti-burglary function (key ID check program) to control programs having no anti-burglary function by erasing the key ID check program. Thus, it is likely that vehicles will be intruded and stolen by using a key which does not have the same ID as stored in the EEPROM.